1. Field of the Invention
The present invention relates to a heel cushion structure for a sneaker which is stalled at the lower edge of the rear of the sneaker, and more particularly to a heel cushion structure which is capable of flexibly adjusting the cushion effect of the sneaker.
2. Description of the Prior Arts
A sneaker is normally provided at its heel portion with an elastic element which is capable of supporting the wearer's weight and cushion the pressure. Vary kinds of elastic units used on the sneaker have become the sneaker producer's selling point. Hence, how to make a better elastic element that can satisfy the wearer's needs has become the most important thing in the sneaker manufacturing trade.
Most of the sneakers on the market are installed in its heel portion with an integral heel cushion structure which is made by elastic ejection, so that the heel block is able to support the weight and to produce a cushion effect. The preferable design is to make an air chamber (so-called air sneaker) inside the heel block. However, this conventional design still has some problems which are explained as follows:
First, the function, the characteristic and the elastic force of the conventional heel cushion cannot be changed once the sneaker is produced. However, different wearers with the same foot size may have different weights. In this case, the sneaker cannot satisfy different wearers' needs who have the same foot size (for example: heavy weight wearer should wear the sneaker with relatively hard heel cushion, and the light weight wearer preferably wear the sneaker with relatively soft heel cushion).
Second, after a certain time of use, the heel cushion of the sneaker will lose elasticity and supporting force gradually (the heel cushion with air chamber will also lose supporting force after the ambient structure is fatigued), especially, the heel cushion with air chamber is likely to be punctured by a sharp object and lose the cushion effect. For this reason, the wearer has to desert the sneaker, so that the problems are arisen, for example, the service life of this conventional sneaker is shortened, the wearer's money is wasted, and even causing an environmental protection problem. If the structure of the heel cushion is enforced (by strengthening the ambient structure), then the elasticity of the heel cushion (or the heel air cushion) will be weakened.
Third, a professional athlete has to wear different sneakers with different function and elasticity according to different situations, such as the ground, the landform and even the weather. Therefore, many different sneakers must be prepared, and this is inconvenient to carry.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.